Screwdriving apparatus are known for driving collated screws. Typical apparatus adapted to drive collated screws include U.S. Pat. No. 4,146,071 to Mueller et al, issued Mar. 27, 1979, U.S. Pat. No. 3,930,297 to Potucek et al, issued Jan. 6, 1976 and U.S. Pat. No. 4,404,877 to Mizuno et al, issued Sep. 20, 1993.
Each of these patents disclose a power tool comprising a screw gun to which a driver attachment is removably coupled by clamping of the driver attachment onto a forwardly extending extension of the housing which is coaxial about a rotatable shaft. The driver attachments are adapted to receive and successively drive screws such as those collated together in a plastic strip in spaced parallel relation. A useful example of such collated screws are disclosed in U.S. Pat. No. 4,167,229 to Keusch et al, issued Sep. 11, 1979 and related Canadian Patents 1,040,600 and 1,054,982 as well as U.S. Pat. No. 4,930,630 to Habermehl, issued Jun. 5, 1990.
Such driver attachments are known to be relatively, easily be coupled to screw guns which have an extension of the housing comprising a cylindrical surface disposed coaxially about the rotating shaft of the screw gun and onto which the driver attachment can be clamped. Of course, this requires complementary sizing of the cylindrical extension of the housing and a clamp mechanism provided as part of the driver attachment. Other complementary attachment systems can be provided and are known including those in which the driver attachment is adapted for threaded engagement onto a threaded cylindrical extension of the housing.
It is desired to secure driver attachments to power drills having chucks which are adjustable to coaxially clamp drill bits and the like therein. However, power drills typically do not have a housing configuration which permits ease of securing of the driver attachment. Most conventionally available power drills do not, in fact, provide any specific surfaces on the drill to permit securing of a driver attachment. Moreover, the configurations of the front portions of known power drills vary widely from manufacturer to manufacturer and from drill to drill with any manufacturer's line of products. A disadvantage thereby arises that there is no universal coupling which is adapted to couple a driver extension to a variety of power drills.
Typical screw guns incorporate a friction clutch mechanism to stop rotation of a threaded fastener to be driven when the torque exceeds a preset amount. Power drills with chucks have the disadvantage that they typically do not provide a clutch mechanism.